Dental tool



(N0 Model-f) G. H. PE-RGE.

DENTALTOUL.

NO. 443,705 Patehted DBO. 30, 189.0.

"UNiTnD STATES Fries..

DENTAL TOOL.

SPECIFICATION forming part of Letters Patent No. 443,705, dated December 30, 1890.

Application filed May 8,1890. Serial No, 351,071. (No model.)

To all whom t may concern:

Be it known that I, GEORGE H. PEIRCE, a

citizen of the United States of America, residing at Vakefield, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Dental Tools, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention relates to that class of dental tools commonly known as a disk carrier or holderg7 and it is the object of my invention to provide a simple form of holdingmandrel adapted to receive the disks with means for clamping the disks securely when in use, the construction being such as to allow the ready removal of the wom disks and the substitution of others.

My invention consists in a mandrel having a face-plate upon its end provided with spurs, a central opening in the `end ofthe mandrel, a head having a screw-threaded stern adapted to the central opening, and a split portion below the faceplate forming a part of the circumference of the mandrel, but not a part ofthe face-plate. This split portion has a series of teeth or a single tooth adapted to engage with the threads of the stem when the said split portion is forced inward by a sliding collar. By this construct-ion I hold the head positively against displacement, at Ithe same time allowing it to be easily removed and as easily inserted.

In the accompanying drawings I have represented the mandrel in side elevation in Figure l, and in Fig. 2 I have shown a central section longitudinally of the end thereof.

The shank of the mandrel, as shown at a, is adapted for connection with any suitable holder, and power may be transmitted to rotate the mandrel in any suitable manner. This forward end is provided with a faceplate h, having a series of 4spurs projecting from its surface, these spurs being adapted to penetrate the material of the disk, which is placed upon them. A central opening passes through the face-plate extending into the body of the mandrel, this opening being perfectly plain, and it is adapted to receive the screw-threaded stem c of the head d, the opening being of a diameter equal to orslight-ly exceeding that of the stem, so that the said stem will slip into the opening easily and be capable of as easy removal. The disk is clamped between the under face of the head and the face-plate, the'spurs preventing independent rotation of the disk.

In order to hold the stem of the head in position I provide the mandrel in rear of the face-plate with a split portion, as at e, this being, preferably, of spring metal, so as to stand normally outside the line of the circumference of the shank of the mandrel. 1 prefer to have thissplit portion made integral at its rear end with the material of the mandrel, though it may be made of a separate piece and held in place by a pivot or otherwise. The inner face of the split portion is provided with a single spur or a series of teeth, which when the split portion is pressed inward engages the threads of the stem, and thus prevents the removal of the head so long as the split part is pressed inward.

I do not limit myself to a threaded stem for the head, as it may be provided with a series of notches or a series of parallel depressions, though it is desirable to have the ordinary spiral thread, as more perfect adjustment can thus be secured. In order to press the split portion inward I arrange a sliding collar or sleeve, which encircles the shank of the mandrel, as shown at f, and as this sleeve lis moved outward toward the end the split portion is pressed inward until its spur or teeth engage with the threaded stem of the head. To remove the head it is only necessary to slide back the sleeve, which will allow the split portion to spring outward, and the head will then be free to be removed.

I claim as my invention- 1. The described dental tool, consisting of a shank or mandrel, a face-plate carried thereby, a central opening passing through the face plate and into the shank, a head having a stem adapted to enter said opening, and a part, as e, having a spur or teeth for engaging said stem, and means for operating said part e, substantially as described.

2. In combination with the mandrel having In testimony whereof nx lnysignntnre in nv face-pint@ with spurs, a split portion in rear presence of two Witnesses.

of YSaid face-plate, n head having a screw threaded stem adapted to enter nu opening GE(`)RGE ll. PIHRCE. 5 in the faceplate and mandrel, said Split p01'- tion having teeth or zu spur for engagement Witnesses:

with the threaded Stem, substantially as de- HENRY H. ARNOLD,

)L J. CHIRAZMN.

scribed. 

